40 Meter Popcorn Superhet Receiver:    This schematic is a relatively low-cost CW superhet receiver with a 4.00 MHz Intermediate frequency. re is no AGC or RF gain control, however this receiver has good large signal handling capability. This receiver uses just 6 bipolar transistors and an op amp for reasonable volume into headphones. Much of  ideas/design of  various stages must  ... (added 02/05)

AGC Amplifier Features 60 DB Dynamic Range:    08/04/05 EDN Design Ideas  / (added 5/02)  Using discrete components only, build an audio-band AGC.

AN-1020: Demodulating with the LMX2240 150 MHz IF Receiver:    National Semiconductor Application Note   (app note added 2/06)

AN-502: Designing a Superheterodyne Receiver using an IF Sampling Diversity Chipset:    AN-502 Analog Devices Application Notes  (app note added 10/06)  The AD6600/AD6620 Chipset Simplifies Receiver Design

Audio Circuit:    Circuit design (added 02/05)

Constant-impedance IF bandpass filters improve circuit performance:    Application Note MiniCircuits.com  (app note added 6/07)

Demodulating with the LMX2240 150 MHz IF Receiver:    National Semiconductor Application Note   (app note added 2/06)

Designing a Superheterodyne Receiver using an IF Sampling Diversity Chipset:    AN-502 Analog Devices Application Notes  (app note added 6/06)  The AD6600/AD6620 Chipset Simplifies Receiver Design

HDT Technology Adds Power to CDMA Chip Set:    RF Micro Devices Application Note TA0003 (added 02/05)

I.F. Amplifier:    The I.F. transformer primary has 18 turns, the secondary winding has 4 turns. The capacitors across the IFT primaries are 82pF. The input/output transformer has 12 turns, tapped at 3 turns from ground. This transformer is wound on a ferrite core. The mosfets are 3SK45's. The diodes in the product detector are 1N34's. I use a six pole SSB filter from a scrap CB. The centre frequency is 7.8MHz. The -6db bandwidth is about 2.5KHz. (added 02/05)

IF Amplifier Circuit:    Three of these amplifiers are used in series to build the 455 kHz IF amplifier. AGC voltage comes from the AGC Circuit. The diagram above shows the circuit for the second IF amplifier. (added 02/05)

LM1823High Quality TV Video I.F. Amplifier and Synchronous Detector for Cable Receivers:    National Semiconductor Application Note 09 Apr1996 / (app note added 6/06)

Low Distortion IF Amplifier/ ADC Driver with Digitally Controlled Gain:    Linear Technology LT5524 (app note added 02/05)

Trimless IF VCO part 2:    Maxim Application Note 688, February 5, 2001 (added 6/06)

Trimless IF VCO: Part 1: Design Considerations:    This application note explores the design fundamentals needed to implement a trimless, fixed-frequency, IF voltage-controlled oscillator (VCO) and points out the challenges in guaranteeing proper circuit operation. VCOs are essential components in the architecture of most wireless systems. In dual-conversion approaches, a fixed-frequency IF VCO is required to control the frequency translation from IF to baseband and/or baseband to IF.   APP 711: Feb 05, 2001  (app note added 6/065)

Tunable IF with TDA7000:    The main motive of the mods was not that the circuit didn't work right, but were several tries to add some kind of frequency indicator to the receiver. The left RCA plug and associated components are witnesses to the last version, adding a FET buffer amplifier and taking signal from the oscillator coil. (added 02/05)

UltraLow Distortion IF Amplifier/ ADC Driver with Digitally Controlled Gain:    Linear Technology LT5514 (app note added 02/05)